Applicatives model computations in which values computed by subcomputations cannot affect what subsequent computations will take place.
Relative to monads, this restriction takes power away from the user of the interface and gives it to the implementation. In particular, because the structure of the entire computation is known, one can augment its definition with some description of that structure.
For more information, see:
Applicative Programming with Effects. Conor McBride and Ross Paterson. Journal of Functional Programming 18:1 (2008), pages 1-13. http://staff.city.ac.uk/~ross/papers/Applicative.pdf
module type Basic : sig ... end
module type Basic_using_map2 : sig ... end
module type S : sig ... end
module type Basic2 : sig ... end
module type Basic2_using_map2 : sig ... end
module type S2 : sig ... end
This module serves mostly as a partial check that S2
and S
are in sync, but
actually calling it is occasionally useful.
module type Args2 : sig ... end
module type Applicative : sig ... end